When remeasuring it turned out that the form does not have 28 cm in diameter, but only just over 26 cm, but I honestly do not care which. Apart from this deficiency, I can still say that the money was well spent.
The form is solid, and absolutely tight in my experience. Just in case, there are also a leakage protection, which can hold some doubt. The non-stick coating keeps its promises, since adheres absolutely nothing on it, not even be consumed. If you want to grease the form anyway (some say yes, then the cake tastes better), can do not only with butter or margarine, but even with oil by the way, unlike Teflon, it does not equal to this ceramic coating down.
Cleaning is also easy as pie I rinse the mold with a soft cloth, and it is clean in no time.
Update 04/22/15:
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Have the form since the purchase regularly in use, and am fully the praise. Never leaked what, never festgepappt what, no signs of use, the part looks as good as new.